Genotypic variation for leaf cadmium concentration in Triticum sp.

Transcription

1 Genotypic variation for leaf cadmium concentration in Triticum sp. Kraljevic-Balalic M., Petrovic S., Dimitrijevic M., Mladenov N. in Molina-Cano J.L. (ed.), Christou P. (ed.), Graner A. (ed.), Hammer K. (ed.), Jouve N. (ed.), Keller B. (ed.), Lasa J.M. (ed.), Powell W. (ed.), Royo C. (ed.), Shewry P. (ed.), Stanca A.M. (ed.). Cereal science and technology for feeding ten billion people: genomics era and beyond Zaragoza : CIHEAM / IRTA Options Méditerranéennes : Série A. Séminaires Méditerranéens; n pages Article available on line / Article disponible en ligne à l adresse : To cite this article / Pour citer cet article Kraljevic-Balalic M., Petrovic S., Dimitrijevic M., Mladenov N. Genotypic variation for leaf cadmium concentration in Triticum sp.. In : Molina-Cano J.L. (ed.), Christou P. (ed.), Graner A. (ed.), Hammer K. (ed.), Jouve N. (ed.), Keller B. (ed.), Lasa J.M. (ed.), Powell W. (ed.), Royo C. (ed.), Shewry P. (ed.), Stanca A.M. (ed.). Cereal science and technology for feeding ten billion people: genomics era and beyond. Zaragoza : CIHEAM / IRTA, p (Options Méditerranéennes : Série A. Séminaires Méditerranéens; n. 81)

2 Genotypic variation for leaf cadmium concentration in Triticum sp. M. Kraljevic-Balalic, S. Petrovic, M. Dimitrijevic and N. Mladenov Faculty of Agriculture, Institute of Field and Vegetable Crops, Novi Sad, Serbia Introduction Cadmium (Cd) belongs to the group of "heavy metals". It is highly toxic to plants and animals (Alloway, 1990). The main source of contamination of soil and crops with cadmium is industrial effluents. Although unnecessary for the plant growth, Cd is readily taken up by their root system and leaves, with its uptake being usually proportional to the Cd concentration present in the environment. High levels of Cd in food crops are a concern in human diets because of possible negative effects on health. Cereal grains represent a large portion of our diet and are therefore a major contributor to Cd intake (Wagner, 1993). The maximum tolerable intake of Cd for humans, recommended by FAO/WHO is 70 g/day (Vasilev and Yordanova, 1997). Chaudri et al. (2001) showed that the Cd concentration in the grain of the wheat genotype Soissons was greater than the EU limit (0.24 mg kg -1 dry wt). The production of crops which do not contain high levels of Cd requires continuous monitoring of the content of trace elements in fertilizers and systematic reduction of effluents emitted to the atmosphere. The aim of the study was therefore to obtain information on genetic variation in the Cd concentration in the leaves of various Triticum sp. Material and methods Variation in the Cd concentration of leaves was investigated under field conditions in thirty genotypes and species of Triticum, originating from different parts of the world (Table 1). The trial was carried out using a randomized complete block design with three replicates during two growing seasons at the experimental station of the Institute of Field and Vegetable Crops, Novi Sad, Serbia. Samples consisted of 10 plants per replicate. The Cd concentration (ppm) in the leaves at heading stage was determined using atomic absorption spectroscopy. Hierarchical cluster analysis, using "Euclidian distance" was employed to order genotypes according to Cd concentration. Calculations were made with STATISTICA 7.0 software. Results and discussion Significant differences were found between the mean values for Cd concentration in the various lines of Triticum. Cd concentration varied between ppm in Triticum aestivum ssp vulgare var. nigracolor to ppm in the cultivar Timgalen, originating from Australia, averaged over two years (Table 1). Genotypic variation in grain Cd concentration has been reported in both bread (Oliver et al., 1995), and durum wheats (Penner et al., 1995). Also, Clarke et al. (1997) showed differences in Cd concentration in the leaves of durum wheat. The average Cd concentration was higher in 2001 than in 2000 (Table 1), which could be due to the climatic conditions in these years. Options Méditerranéennes, Series A, No

3 Table 1. The Triticum genotypes and their leaf Cd concentrations measured at heading stage No. Genotype Origin Genome Cd concentration (ppm) Average 1. Tr. dicoccoides LV AB Tr. polonicum var. gracila LV AB Tr. turgidum var. LV AB nigrobarbatum Tr. durum var. cerulescens LV AB Tr. durum hordeiformae LV AB Tr. dicoccum var. forrum LV AB Tr. dicoccum var. africanum LV AB NS Rana 5 YUG ABD NSD 1/93 YUG AB Triticum macha LV ABD Triticum spelta LV ABD Pobeda YUG ABD Triticum aestivum ssp. LV ABD vulgare var. nigracolor 14. Chinese Spring CHI ABD Tr. paleocolch. var. vulpinum LV AB Rodna YUG ABD Frontana BRA ABD Renesansa YUG ABD Libelulla ITA ABD Trakija BGR ABD Odeskaya 51 RUS ABD Peking 11 CHI ABD Evropa 90 YUG ABD Timgalen AUS ABD Bezostaya 1 RUS ABD Partizanka YUG ABD Kavkaz RUS ABD Nevesinjka YUG ABD GK Othalom HUN ABD Kalyan Sona IND ABD Average G Y G/Y LSD LSD Highly significant differences were found for all sources of variation. The Cd concentration was predominantly influenced by the year of growth (73%). The genotype accounted for 16% of the variation in Cd concentration and the genotype x year interaction for 11% (Table 2). Leaf Cd concentration is highly correlated with grain Cd concentration, as reported by Clarke et al. (1997). The leaf Cd concentration could therefore be used to identify lines with low levels of grain Cd accumulation for exploitation in plant breeding. In durum wheat the heritability for Cd concentration was high and the inheritance simple. In our experiment the leaf Cd concentration was higher in tetraploid than in hexaploid wheat genotypes (Table 1) which is in agreement with the report of Meyer et al. (1982). These authors also reported higher levels of Cd in durum than in bread wheat. 312 Options Méditerranéennes, Series A, No. 81

4 Table 2. ANOVA for Cd concentration in the leaves of Triticum sp. (heading stage) Source of variation Df MS Value % Fe Genotype (G) ** Year (Y) ** G/Y ** E Cluster analysis divides the genotypes into five groups based on the Cd concentrations in their leaves. The genotype Timgalen (24), with highest mean value for Cd concentration, could be considered to form an independant group. The genotypes which contained the least Cd are Kalyan Sona (30), Partizanka (26) and NS Rana 5 (8) belonging to groups IV or III. They could therefore be used as parents for hybridization to transfer the low Cd trait to other genotypes (Fig. 1). G e n o t y p e s Linkage Distance 7 Fig. 1. Dendrogram of Cd concentration in Triticum sp. References Alloway, B. (1990). Cadmium. In: Heavy Metals in Soil, Alloway, B. (ed.). John Wiley & Sons, New Jersey, pp Ciecko, Ž., Wzsykowskz, M., Krajevski, W. and Zabielska, J. (2001). Effect of organic matter and liming on the reduction of cadmium uptake from soil by triticale and spring oilseed rape. The Science of the Total Environment, 281: Chaudri A.M., Allan, C.M.G., Badawy, S.H., Adams, M.L., McGrath, S.P. and Chambers B.J. (2001). Cadmium content of wheat grain from a long-term field experiment with sewage sludge. Journal of Environmental Quality, 30: Clarke, J.M., Leisle, D. and Kopytko, G.L. (1997). Inheritance of cadmium concentration in five durum wheat crosses. Crop Science, 37: Options Méditerranéennes, Series A, No

5 Meyer, M.W., Fricke, F.L., Homgren, G.G.S., Kubota, J. and Chaney, R. (1982). Cadmium and lead in wheat grain and association surface soils of major wheat production areas in United States. In: Agron. Abstracts, p. 34. Oliver, D.P., Gartrell, J.P., Tiller, K.G., Correl, R., Cozens, G.D. and Youngberg, B.L. (1995). Differential responses of Australian wheat cultivars to cadmium concentration in wheat grain. Australian Journal of Agricultural Research, 46: Penner, G.A., Clarke, J.M, Bezte, L.J. and Leisle, D. (1995). Identification of RAPD markers linked to a gene governing cadmium uptake in durum wheat. Genome, 38: Vasilev, A. and Yordanov, J. (1997). Reductive analysis of factors limiting growth of cadmium-treated plants. Bulgarian Journal of Plant Physiology, 23: Wagner, G. (1993). Accumulation of cadmium in crop plants and its cosequences to human health. Advances in Agronomy, 51: Options Méditerranéennes, Series A, No. 81